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101.
A. V. Ratna Prasad K. Balakotesara Rao K. Mohana Rao K. Ramanaiah S. P. Kumar Gudapati 《International Journal of Polymer Analysis and Characterization》2015,20(6):541-556
Natural fiber-reinforced nanocomposites were prepared by incorporating wild cane grass fiber and organically modified montmorillonite (MMT) nanoclay into polyester resin. The composites were formulated up to a maximum volume of fiber of approximately 40% and their mechanical properties were investigated. The mean tensile strength and tensile modulus of nanoclay-filled wild cane grass fiber composites are 6.3% and 18.3% greater than those of wild cane grass fiber composites, respectively, without addition of nanoclay at maximum percentage volume of fiber. The mean flexural strength of nanocomposites at maximum percentage volume of fiber was increased to a maximum of 221 Mpa and flexural modulus to 4.2 Gpa. The mean impact strength of nanoclay-filled wild cane grass fiber composites was increased to 376.7 J/m at maximum percentage volume of fiber. The weight loss of nanoclay-filled wild cane grass fiber/polyester composites was 30% and 22% less than that of composites without nanoclay at maximum percentage volume of fiber. The results indicated that the use of nanoclay showed significant improvement in all the mechanical properties of wild cane grass fiber-reinforced composites. 相似文献
102.
The potential of using ensiling, with and without supplemental enzymes, as a cost-effective pretreatment for bioethanol production from agricultural residues was investigated. Ensiling did not significantly affect the lignin content of barley straw, cotton stalk, and triticale hay ensiled without enzyme, but slightly increased the lignin content in triticale straw, wheat straw, and triticale hay ensiled with enzyme. The holocellulose (cellulose plus hemicellulose) losses in the feedstocks, as a result of ensiling, ranged from 1.31 to 9.93%. The percent holocellulose loss in hays during ensiling was lower than in straws and stalks. Ensiling of barley, triticale, wheat straws, and cotton stalk significantly increased the conversion of holocellulose to sugars during subsequent hydrolysis with two enzyme combinations. Enzymatic hydrolysis of ensiled and untreated feedstocks by Celluclast 1.5 L-Novozyme 188 enzyme combination resulted in equal or higher saccharification than with Spezyme CP-xylanase combination. Enzyme loadings of 40 and 60 FPU/g reducing sugars gave similar sugar yields. The percent saccharification with Celluclast 1.5 L-Novozyme 188 at 40 FPU/g reducing sugars was 17.1 to 43.6%, 22.4 to 46.9%, and 23.2 to 32.2% for untreated feedstocks, feedstocks ensiled with, and without enzymes, respectively. Fermentation of the hydrolysates from ensiled feedstocks resulted in ethanol yields ranging from 0.21 to 0.28 g/g reducing sugars. 相似文献
103.
Chen Y Sharma-Shivappa RR Keshwani D Chen C 《Applied biochemistry and biotechnology》2007,142(3):276-290
Production of bioethanol from agricultural residues and hays (wheat, barley, and triticale straws, and barley, triticale, pearl millet, and sweet sorghum hays) through a series of chemical pretreatment, enzymatic hydrolysis, and fermentation processes was investigated in this study. Composition analysis suggested that the agricultural straws and hays studied contained approximately 28.62-38.58% glucan, 11.19-20.78% xylan, and 22.01-27.57% lignin, making them good candidates for bioethanol production. Chemical pretreatment with sulfuric acid or sodium hydroxide at concentrations of 0.5, 1.0, and 2.0% indicated that concentration and treatment agent play a significant role during pretreatment. After 2.0% sulfuric acid pretreatment at 121 degrees C/15 psi for 60 min, 78.10-81.27% of the xylan in untreated feedstocks was solubilized, while 75.09-84.52% of the lignin was reduced after 2.0% sodium hydroxide pretreatment under similar conditions. Enzymatic hydrolysis of chemically pretreated (2.0% NaOH or H2SO4) solids with Celluclast 1.5 L-Novozym 188 (cellobiase) enzyme combination resulted in equal or higher glucan and xylan conversion than with Spezyme(R) CP- xylanase combination. The glucan and xylan conversions during hydrolysis with Celluclast 1.5 L-cellobiase at 40 FPU/g glucan were 78.09 to 100.36% and 74.03 to 84.89%, respectively. Increasing the enzyme loading from 40 to 60 FPU/g glucan did not significantly increase sugar yield. The ethanol yield after fermentation of the hydrolyzate from different feedstocks with Saccharomyces cerevisiae ranged from 0.27 to 0.34 g/g glucose or 52.00-65.82% of the theoretical maximum ethanol yield. 相似文献
104.
Ratna Tantra Richard J. C. Brown Martin J. T. Milton 《Journal of Raman spectroscopy : JRS》2007,38(11):1469-1479
There is a pressing need to improve the reproducibility of surface enhanced Raman spectroscopy (SERS) measurements, if the technique is to be used routinely for trace analysis. This is particularly true for colloidal SERS, in which data reproducibility is dominated by the final shape and size of metal clusters produced during colloid aggregation. This study presents general guidelines for designing appropriate measurement strategies that can be used to identify and optimise crucial steps in a protocol that leads to better reproducibility of the results. We show that the data reproducibility can be improved by optimising vortexing time during colloid aggregation, which we attribute to the formation of more reproducible metal clusters under conditions of ‘forced convection’. The study also investigated the effects of different storage conditions on the data reproducibility of SERS during a 6‐month study period. Storage conditions did not significantly influence the SERS reproducibility. However, at the end of 6 months, colloids that were stored (in plastic containers) at room temperature showed a difference in their quality, as mirrored by their different opto‐physical properties. This was made apparent through the analysis of UV‐vis spectroscopy measurements by principal component analysis. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
105.
We discuss a computationally tractable approach to the valuation of multiname credit derivatives employing name grouping for dimension reduction, and singular perturbation approximations for model robustness. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
106.
Parametric Study of a Pressure Swing Adsorption Process 总被引:2,自引:0,他引:2
The performance of a pressure swing adsorption (PSA) process for production of high purity hydrogen from a binary methane-hydrogen mixture is simulated using a detailed, adiabatic PSA model. An activated carbon is used for selective adsorption of methane over hydrogen. The effects of various independent process variables (feed gas pressure and composition, purge gas pressure and quantity, configuration of process steps) on the key dependent process variables (hydrogen recovery at high purity, hydrogen production capacity) are evaluated. It is demonstrated that many different combinations of PSA process steps, their operating conditions, and the feed gas conditions can be chosen to produce an identical product gas with different hydrogen recovery and productivity. 相似文献
107.
Mohite Neeta Shinde Manish Gupta Arun Kumar Waghadkar Yogesh Gosavi Suresh W. Mohite K. C. Chauhan Ratna Rane Sunit 《Journal of Solid State Electrochemistry》2020,24(2):273-281
Journal of Solid State Electrochemistry - In present study, hollow urchin-like nanostructures of Nb2O5 with elongated nanofilaments as photoanode material for dye-sensitized solar cells (DSSCs) are... 相似文献
108.
Bhowmik Ratul Manaithiya Ajay Vyas Bharti Nath Ranajit Rehman Sara Roy Shubham Roy Ratna 《Structural chemistry》2022,33(3):815-831
Structural Chemistry - The Ebola virus is a deadly pathogen that causes a highly lethal hemorrhagic fever illness in humans, sometimes known as Ebola virus sickness (EVD). The Ebola virus... 相似文献
109.
Abhinav Kumar Ratna Chauhan Kieran C. Molloy Prof. Gabriele Kociok‐Köhn Dr. Lal Bahadur Prof. Nanhai Singh Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(14):4307-4314
Nine new transition‐metal dithiocarbamates involving ferrocene (Fc), namely, [M(FcCH2Bzdtc)2] (M=NiII ( 1 ), CuII ( 2 ), CdII ( 3 ), HgII ( 4 ), PdII ( 5 ), PtII ( 6 ) and PbII ( 7 ); Bzdtc=N‐benzyl dithiocarbamate) and [M(FcCH2Bzdtc)3] (M=CoII ( 8 ) and UO2VI ( 9 )), have been synthesised and characterised by micro analyses, IR spectroscopy, 1H and 13C NMR spectroscopy, and in three cases by single‐crystal X‐ray analysis. The peak broadening in the 1H spectrum of the copper complex indicates the paramagnetic behaviour of this compound. A square‐planar geometry around the nickel and copper complexes and distorted linear geometry around the mercury complex have been found. The latter geometry is attributed to the bulkiness of the methylferrocenyl and benzyl groups. The observed single quasi‐reversible cyclic voltammograms for complexes 2 , 8 and 9 indicate the stabilisation of a metal centre other than Fe in their characteristic oxidation state. These complexes have been used as a photosensitiser in dye‐sensitised solar cells. 相似文献
110.
The effects of the sorption and the regeneration temperatures on the performance of a novel rapid thermal swing chemisorption
(RTSC) process (Lee and Sircar in AIChE J. 54:2293–2302, 2008) for removal and recovery of CO2 from an industrial flue gas without pre-compression, pre-drying, or pre-cooling of the gas were mathematically simulated.
The process directly produced a nearly pure, compressed CO2 by-product stream which will facilitate its subsequent sequestration. Na2O promoted alumina was used as the CO2 selective chemisorbent, and the preferred temperatures were found to be, respectively, 150 and 450 °C for the sorption and
regeneration steps of the process. The specific cyclic CO2 production capacity of the process and the pressure of the by-product CO2 gas were substantially increased over those previously achieved by using the sorption and regeneration temperature of, respectively,
200 and 500 °C (Lee and Sircar in AIChE J. 54:2293–2302, 2008). The net compressed CO2 recovery from the flue gas (∼92%) did not change. However, substantially different amounts of high and low pressure steam
purges were necessary for comparable degree of desorption of CO2. A first pass estimation of the capital and the operating costs of the RTSC process was carried out for a relatively moderate
size application (flue gas clean up and CO2 recovery from a ∼80 MW coal fired power plant). Both costs were substantially lower than those for a conventional absorption
process using MEA as the CO2 solvent (Desideri and Paolucci in Energy Convers. Manag. 40:1899–1915, 1999). 相似文献